Process variations in circuits (or device variations) impact the quality and yield of circuits such as filters. The parameters of semiconductor circuits can vary from lot to lot, wafer to wafer, die to die, or device to device. These variations can degrade the circuit performance and produce low circuit yield. The values of circuit components such as resistors may vary +/−20% of the target values, and the values of circuit components such as capacitors may also vary +/−20% of the target values. Furthermore, some resistors and capacitors may have values that deviate more than 20% from the target values.